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Study of properties of ultrashort femtosecond pulses
Hamráček, Karol ; Trojánek, František (advisor) ; Surýnek, Miloslav (referee)
Title: Study of the properties of ultra-short femtosecond pulses Author: Karol Hamráček Department: Department of chemical physics and optics Supervisor: doc. RNDr. František Trojánek, Ph.D. Abstract: Even as a bachelor thesis, the ultra-short pulses produced by the Rainbow CEP4 PRo laser system are about 7 fs long. This implies a very wide spectrum of these pulses, which can be up to 300 nm wide. This is why the ultrashort pulse will be lengthen by passing through a common dispersive medium such as the optical system of the classical optical elements, since each wavelength in the spectrum will propagate differently in the environment and will therefore overtake each other, resp. they will lag behind each other. Our aim will be to study this issue and to deal with the behavior of ultra-short pulses in different media. Keywords: ultra-short pulse, UV area, second harmonic wave
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Optical spectroscopy of magnetically ordered materials
Surýnek, Miloslav ; Němec, Petr (advisor) ; Němec, Hynek (referee)
Spintronics is a dynamically developing branch of electronics which for transfer, processing and storing of information use not only electron charge but also its spin. Materials appropriate for a construction of spintronic devices should sustain the spin order for a sufficiently long time enabling a manipulation of spins. Simultaneously, in these materials the spin of electrons should be possible to transport fast and long enough across the device. In this work, heterostructure of GaAs/AlGaAs fulfilling these requirements is investigated by a pump-probe technique. In particular, long spin lifetimes of electrons in the heterostructure are studied using the resonant spin amplification method and with a use of the pulse picker. The nuclear spin polarization and the effect of an applied electric current on the studied heterostructure are also investigated in this work. Spectral filters are used to improve the existing experimental setup for the pump-probe technique and to measure a magnetooptical spectrum of the investigated heterostructure.
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Laser spectroscopy with high spatial resolution
Surýnek, Miloslav ; Němec, Petr (advisor) ; Preclíková, Jana (referee)
Spintronics is a fast developing branch of electronics, which uses for data storage and processing not only the electric charge of electrons, but also their spin. However, for a research of materials which can be used for a construction of spintronic devices it is necessary to use experimental methods that are able to achieve both high temporal and spatial resolutions. In Laboratory of Optospintronics at the Department of Chemical Physics and Optics there is currently developed a method based on Kerr microscope, which is expected to achieve a high spatial resolution and in a future also a high temporal resolution. The goal of this thesis is to characterize some parts of the experimental setup: Namely, a characterization of the laser speckle reducer LSR-3005-24D made by Optotune and a characterization of the piezo-driven mirror mount CONEX-AG-M100D made by Newport. Powered by TCPDF (www.tcpdf.org)
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